Deburring tool and deburring method

ABSTRACT

A deburring method includes rotating a case, a sleeve and a drive gear together with a spindle of a machining tool; transmitting rotating torque from the drive gear to a driven gear to rotate a tip tool together with a reciprocating shaft; receiving reactive torque to the tip tool in a reverse direction of a rotational direction of the case by a workpiece contact with the tip tool so that the reciprocating shaft rotates in a reverse direction of the rotational direction with respect to the sleeve; moving the reciprocating shaft to a basal end direction against an elastic force of a second spring with the driven gear sliding with respect to the drive gear; and cutting the workpiece by the tip tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is division of application Ser. No. 17/060,559, filedon Oct. 1, 2020, which claims the benefit of priority to Japanese PatentApplication No. 2019-187823, filed on Oct. 11, 2019, and Japanese PatentApplication No. 2020-146086, filed on Aug. 31, 2020, the entire contentsof which are hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present invention relates to a deburring tool and a deburringmethod.

2. Description of the Background

A conventional deburring tool includes a shank, and a stem movable inthe axial direction with respect to the shank, and a cutting toolholding unit for holding a cutting tool, a tool guide unit for guidingthe cutting tool holding unit in the axial direction with respect to thestem, and a spring for pressing the cutting tool holding unit against aworkpiece with respect to the stem, and an initial length adjustmentunit for adjusting the initial length of the spring. The conventionaldeburring tool is mounted on a spindle device of the machining tool (Forexample, Japanese Patent No. 6025580).

BRIEF SUMMARY

The deburring tool of Japanese Patent No. 6025580 sometimes excessivelyshaves the workpiece or insufficiently shaves the workpiece depending onthe shape and position of the workpiece.

An object of the present invention is to provide a deburring tool and adeburring method capable of performing a uniform deburring process.

An aspect of the present invention provides a deburring method,including:

-   -   rotating a case, a sleeve and a drive gear together with a        spindle of a machining tool;    -   transmitting rotating torque from the drive gear to a driven        gear to rotate a tip tool together with a reciprocating shaft;    -   receiving reactive torque to the tip tool in a reverse direction        of a rotational direction of the case by a workpiece contact        with the tip tool so that the reciprocating shaft rotates in a        reverse direction of the rotational direction with respect to        the sleeve;    -   moving the reciprocating shaft to a basal end direction against        an elastic force of a second spring with the driven gear sliding        with respect to the drive gear; and    -   cutting the workpiece by the tip tool.

The tip tool is, for example, a so-called rotary bar or brush. Therotary bar is, for example, a cutting tool in which a large number ofcutting edges are arranged on the surface of a rod-shaped or egg-shapedcemented carbide metal base material. The brush is, for example, acylindrical brush, and is used for deburring the tip surface. Thebristle material of the brush is, for example, ceramic, or metal.

The sleeve is hollow cylindrical. The outer surface of the sleeve slideson the inner surface of the cylinder. Preferably, the sleeve includes astopper. The stopper restricts the movement of the reciprocating shafttoward the basal end. The axial moving length of the reciprocating shaftrelative to the sleeve is the distance between the stopper and thedriven gear. A tool holder slides on the inner surface of the sleeve.

The drive gear includes a first tooth on the end face of the basal endside. The driven gear includes a second tooth on the end face of thedistal end side. The first and second teeth mesh and transmit rotationof the first tooth to the second tooth. When the tip tool comes intocontact with the workpiece and receives the cutting torque, the secondtooth slides relative to the first tooth, and the driven gear movestoward the basal end. The first tooth has a first sliding surface whichis inclined so as to be positioned on the distal end side as it advancesin the rotational direction. Preferably, the intersection line betweenthe first sliding surface and the cylindrical surface having a rotationaxis at the center of the deburring tool draws a spiral. The secondtooth has a second sliding surface which is inclined so as to bepositioned on the distal end side as it advances in the rotationaldirection. The first sliding surface slides with the second slidingsurface.

One or more of the first ball holding hole, the first ball, and thefirst roller groove may be disposed. The number of the first ballholding holes and the number of the first roller grooves are the same.The first ball is arranged between the first ball holding hole and thefirst roller groove. Preferably, a plurality of first ball holes, thefirst balls and the first roller grooves are evenly arranged on thecircumference. Preferably, two to four first ball holding holes arearranged. More preferably, two first ball holes are arranged.

The first ball holding hole extends along the radial direction. Thefirst ball holding hole may be a through hole. A hollow holding cylinderfor holding the first ball may be disposed on the outer periphery of thefirst ball holding hole. The holding cylinder is fixed to the cylinder.

One or more of the second ball holding hole and the second ball may bedisposed. Preferably, a plurality of the second ball holding holes areevenly arranged on the circumference. The second balls are respectivelyarranged in the second ball holding hole. For example, two to foursecond ball holding holes may be arranged. Preferably, three second ballholding holes and second balls are arranged.

The second ball holding hole may extend radially. The second ball may beheld sandwiched between the inner surface of the inner cylinder and thesecond roller groove.

The second ball holding hole, the second roller groove, and the secondball may be omitted.

The drive gear may have a hemispherical third ball holding hole arrangedon the outer peripheral surface of the drive gear. The sleeve may have afourth ball holding hole of the same number as the third ball holeinside of the sleeve. A third ball is arranged between the third ballholding hole and the fourth ball holding hole. A plurality of the thirdball holding holes and the fourth ball holding holes are arranged on thecircumference. For example, two to four third ball holes are arranged.Preferably, three third ball holes are arranged. In this case, the drivegear is supported on the sleeve via the ball.

The third ball may be a pin for the purpose of supporting the drive gearwith the sleeve. The pin extends radially. In this case, a third pinhole is provided instead of the third ball hole. A fourth pin hole isprovided instead of the fourth ball hole. The third pin hole and thefourth pin hole are arranged through the sleeve, for example. The pin isimplanted in the fourth pin hole and passes through the third pin hole.

The fourth ball holding hole may extend radially. The third ball may beheld sandwiched between the fourth ball holding hole and the innercylindrical surface of the cylinder.

The drive gear may be fixed inside the sleeve instead of being supportedby the third ball holding hole, the fourth ball holding hole, and thefourth ball.

The driven gear reciprocates in the sleeve while rotating. The secondtooth of the driven gear moves in the sleeve to the basal end directionwhile rotating in the reverse direction to the rotation direction of thetool with respect to the drive gear while rubbing with the first toothof the drive gear.

The second balls, which are evenly arranged on the circumference, aresupported by the cylinder to hold the tool holder at the center positionof the cylinder.

The pushing force from the second spring to the reciprocating shaft actsas a frictional force between the sliding surface of the drive gear andthe sliding surface of the driven gear, and torque is transmitted fromthe drive gear to the driven gear.

The sliding surface of the driven gear slides against the slidingsurface of the drive gear by the elastic force of the second springagainst the frictional force generated between the sliding surface ofthe drive gear and the sliding surface of the driven gear.

The deburring tool and the deburring method according to the presentinvention achieves uniform deburring.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a tool according to anembodiment.

FIG. 2 is a perspective view of a sleeve according to the embodiment.

FIG. 3 is a perspective view of a drive gear and a reciprocating shaftaccording to the embodiment.

FIG. 4 is a longitudinal cross-sectional view showing the tool in useaccording to the embodiment.

FIG. 5 is a longitudinal cross-sectional view showing the tool in useaccording to the embodiment.

DETAILED DESCRIPTION

As shown in FIG. 1, a deburring tool 10 of the present embodimentincludes a case 15, a sleeve 17, a first spring 21, a drive gear 29, areciprocating shaft 49, and a second spring 53. The case 15 includes ashank 11 and a cylinder 13. The reciprocating shaft 49 includes a drivengear 43, a stem 45, and a tool holder 47 in the order from a basal end.The deburring tool 10 may include a stopper 19, a first ball holdinghole 23, a first roller groove 25, a first ball 27, a ball holdingcylinder 24, a third ball holding hole 35, a fourth ball holding hole31, a third ball 33, a second ball holding hole 59, a second rollergroove 55, and the second ball 57. The shank 11 is mounted, for example,on the spindle of a machining tool which is a machining center. Thedeburring tool 10 is used by rotating in the direction of the rotationdirection 7 together with the spindle.

The shank 11 is a straight shank. The shank 11 is disposed at the basalend of the cylinder 13, and includes a spring housing hole 11 a. Thespring housing hole 11 a is a right cylinder. The spring housing hole 11a is disposed inside the shank 11 along the center of the shank 11.

The cylinder 13 has an inner surface 13 a. The inner surface 13 a is aright cylinder. The inner surface 13 a is disposed inside the cylinder13 along the center of the cylinder 13, and connects to the springhousing hole 11 a.

The sleeve 17 is a hollow cylindrical shape, and has an outer peripheralsurface 17 a and an inner surface 17 b. The sleeve 17 reciprocatesinside the cylinder 13 in the axial direction in a non-rotating manner.The outer peripheral surface 17 a of the sleeve 17 slides on the innersurface 13 a of the cylinder 13.

The stopper 19 is disposed at the basal end of the sleeve 17. The outerperipheral surface 17 a of the sleeve 17 is guided to the inner surface13 a of the cylinder 13. The stopper 19 defines a moving length 63 ofthe driven gear 43 toward the basal direction.

The first spring 21 is, for example, a compression coil spring. Thefirst spring 21 is disposed inside the spring housing hole 11 a. Thefirst spring 21 pushes the sleeve 17 toward the distal end direction.

The first ball holding hole 23 is located at the central portion of theinner surface 13 a in the axial direction. For example, two first ballholding holes 23 are equally spaced on the circumference. The first ballholding hole 23 is a cylindrical hole extending in the radial direction.The first ball holding hole 23 penetrates the cylinder 13.

The first ball holding hole 23 may be, for example, hemispherical, or acylindrical hole having a bottom. In this case, the ball holdingcylinder 24 is omitted.

As shown in FIG. 2, the first roller groove 25 has a semicircularcross-section and extends in the axial direction. A plurality (e.g.,two) of the first roller groove 25 is disposed in the circumferentialdirection on the outer peripheral surface 17 a of the sleeve 17. Thelength of the first roller groove 25 determines the moving amount of thesleeve 17 in the axial direction with respect to the cylinder 13.

The first ball 27 is disposed between the first ball holding hole 23 andthe first roller groove 25. The first ball 27 rolls in the first rollergroove 25, and the sleeve 17 reciprocates in the axial direction. Thefirst ball 27 is held in the first ball holding hole 23 by rolling inthe first roller groove 25 to regulate the rotation of the sleeve 17.

The ball holding cylinder 24, which is a hollow cylinder, is disposedoutside the first ball 27, and presses the first ball 27 radiallyinward. The ball holding cylinder 24 is fixed to the cylinder 13. Theball holding cylinder 24 restricts the first ball 27 to move outward inthe radial direction.

As shown in FIG. 3, the drive gear 29 includes a saw blade shaped firsttooth 29 a, and a through hole 29 b. The first tooth 29 a has a firstsliding surface 29 a 1. The first sliding surface 29 a 1 extendshelically along the circumference so as to advance toward the distal enddirection as it moves in the rotation direction 7. The height 65 of thefirst tooth 29 a is larger than the moving length 63. The through hole29 b extends along the rotation axis 3.

Four third ball holding holes 35 are disposed in the drive gear 29. Thethird ball holding hole 35 is hemispherical. The third ball holdingholes 35 are evenly arranged on the circumference.

As shown in FIG. 1, the four fourth ball holding holes 31 are evenlyarranged in the circumferential direction. For example, the fourth ballholding hole 31 are arranged on the basal end side than the first rollergroove 25. The fourth ball holding hole 31 is a through hole extendingin the radial direction.

The third ball 33 is disposed between the fourth ball holding hole 31,the third ball holding hole 35, and the inner surface 13 a. The thirdball 33 supports the drive gear 29 in the sleeve 17. The third ball 33transmits the rotation of the sleeve 17 to the drive gear 29.

The driven gear 43 includes a second tooth 43 a. The second tooth 43 ahas a second sliding surface 43 a 1. The second tooth 43 a meshes withthe first tooth 29 a. The second sliding surface 43 a 1 slides with thefirst sliding surface 29 a 1.

The stem 45 is a right cylinder and penetrates through the through hole29 b. The stem 45 fixes the driven gear 43 and the tool holder 47. A gapmay be provided between the stem 45 and the through hole 29 b. The stem45 may slide with respect to the through hole 29 b.

The stem 45 may have a T-shaped or L-shaped communication hole (notshown). The communication hole connects the space above the driven gear43 and the space below the drive gear 29. The communication hole movesthe air in the cylinder 13 when the reciprocating shaft 49 reciprocates.

The tool holder 47 is hollow cylindrical and has an outer cylindricalsurface 47 a and a shank hole 47 b. The tool holder 47 is disposedinside the inner surface 17 b of the sleeve 17.

The outer cylindrical surface 47 a is a right cylinder, and slides withthe inner surface 17 b of the sleeve 17.

The shank hole 47 b is located at the distal end portion of the toolholder 47 along the rotation axis 3. The rotation cutting tool (tiptool) 61 is mounted to the shank hole 47 b. The rotation cutting tool 61includes a cutting edge 61 a at the distal end. A collet (not shown) maybe disposed in the shank hole 47 b. The collet fastens the rotationcutting tool 61 to the tool holder 47.

The three second ball holding holes 59 are located at the distal end ofthe sleeve 17. The second ball holding holes 59 are evenly arranged onthe circumference. The second ball holding hole 59 is, for example, athrough hole extending in the radial direction.

The second roller groove 55, which is a circumferential groove, isarranged on the outer cylindrical surface 47 a. The second roller groove55 has substantially the same length as the moving length 63 in theaxial direction. The second roller groove 55 may be longer than themoving length 63.

The three second balls 57 are inserted between the inner surface 13 a ofthe cylinder 13, the second ball holding hole 59, and the second rollergroove 55, and roll inside the second roller groove 55. The three secondballs 57, which are arranged evenly on the circumference, are supportedby the cylinder 13 to hold the tool holder 47 in the center position ofthe cylinder 13.

The second spring 53 is, for example, a compression coil spring. Thesecond spring 53 is mounted between the tool holder 47 and the drivegear 29. The second spring 53 has a greater elastic force than the firstspring 21. The second spring 53 pushes the reciprocating shaft 49 towardthe distal end with respect to the drive gear 29. The pushing force withwhich the second spring 53 pushes the reciprocating shaft 49 acts as africtional force between the second sliding surface 43 a 1 and the firstsliding surface 29 a 1, thus torque is transmitted from the drive gear29 to the driven gear 43.

Next, the operation of the deburring tool 10 will be described.

The deburring tool 10 rotates with the spindle of the machining tool.The rotation is transmitted to the rotation cutting tool 61 via thefirst ball 27, the sleeve 17, the drive gear 29, and the driven gear 43.When the cutting edge 61 a receives an axial thrust force in contactwith the workpiece 5, as shown in FIG. 4, the sleeve 17 moves againstthe elastic force of the first spring 21 to the basal direction. Sincethe outer peripheral surface 17 a of the sleeve 17 slides on the innersurface 13 a of the cylinder 13, the sleeve 17 moves accurately. Sincethe first ball 27 rolls in the first roller groove 25, the sleeve 17moves along the direction of the rotation axis 3 without rotation.

When the rotation cutting tool 61 receives the cutting torque, as shownin FIG. 5, the second sliding surface 43 a 1 of the driven gear 43slides relative to the first sliding surface 29 a 1 of the drive gear 29against the frictional force generated between the second slidingsurface 43 a 1 and the first sliding surface 29 a 1 by the elastic forceof the second spring 53. Then, the reciprocating shaft 49 moves in thebasal direction while rotating in the reverse direction of the rotationdirection 7.

Even if the position of the workpiece 5 varies, the reciprocating shaft49 is advanced and retracted such that the cutting torque becomesconstant with respect to the workpiece 5 in accordance with the thrustload and the radial load received from the workpiece 5, thus the cuttingamount by the cutting edge 61 a is adjusted. As a result, regardless ofthe position of the deburring target surface of the workpiece 5, aconstant cutting amount is maintained.

Further, by mounting the ceramic brush, which is a tip tool, todeburring tool 10, when contacting the ceramic brush to the workpiece 5from the lateral direction, the tool holder 47 is raised in accordancewith the torque. Therefore, it is possible to suppress damage to theceramic brush and deburring tool 10.

Further, when deburring by using the deburring tool 10 according to thepresent embodiment, the machined surface after deburring became smooth.

It should be noted that the present invention is not limited to theembodiments described above, and various modifications can be madewithout departing from the gist of the present invention, and alltechnical matters included in the technical idea described in the claimsare the study matter of the present invention. While the foregoingembodiments illustrate preferred examples, those skilled in the art willappreciate that various alternatives, modifications, variations, orimprovements may be made in light of the teachings disclosed herein andare within the scope of the appended claims.

REFERENCE SIGNS LIST

-   5 Workpiece-   10 Deburring tools-   11 Shank-   13 Cylinder-   15 Case-   17 Sleeve-   21 First spring-   29 Drive gear-   43 Driven gear-   45 Stem-   47 Tool holder-   49 Reciprocating shaft-   53 Second spring

What is claimed is:
 1. A deburring method, comprising: rotating a case,a sleeve and a drive gear together with a spindle of a machining tool;transmitting rotating torque from the drive gear to a driven gear torotate a tip tool together with a reciprocating shaft; receivingreactive torque to the tip tool in a reverse direction of a rotationaldirection of the case by a workpiece contact with the tip tool so thatthe reciprocating shaft rotates in a reverse direction of the rotationaldirection with respect to the sleeve; moving the reciprocating shaft toa basal end direction against an elastic force of a second spring withthe driven gear sliding with respect to the drive gear; and cutting theworkpiece by the tip tool.
 2. The deburring method according to claim 1,further comprising: receiving thrust load to the tip tool from theworkpiece; and moving the sleeve toward a basal end direction against anelastic force of a first spring.
 3. The deburring method according toclaim 1, further comprising: rotating the driven gear in the reversedirection of the rotational direction of the tip tool with respect tothe drive gear while rubbing with the drive gear to move in the sleeveto the basal end direction.
 4. The deburring method according to claim2, further comprising: rotating the driven gear in the reverse directionof the rotational direction of the tip tool with respect to the drivegear while rubbing with the drive gear to move in the sleeve to thebasal end direction.